TITLE:
Instability of the lumbar spine due to disc degeneration. A finite element simulation
AUTHORS:
Elena Ibarz, Yolanda Más, Jesús Mateo, Antonio Lobo-Escolar, Antonio Herrera, Luis Gracia
KEYWORDS:
Lumbar Spine; Finite Elements; Biomechanics; Kinematics; Mobility; Disc Degeneration
JOURNAL NAME:
Advances in Bioscience and Biotechnology,
Vol.4 No.4,
April
19,
2013
ABSTRACT:
Low back pain, which most
common cause is degenerative disc disease, currently represents a serious problem due to its socio-economic repercussions. Different
factors are involved in the degenerative process, being the most common: the
loads on the spine, repeated flexion movements and individual genetic characteristics.
Nowadays, there is no agreement on whether instability is the main cause of
low back pain, or only one reason among many, and on whether increased spinal
mobility, associated with instability, occurs either locally or at the lumbar
spine as a whole. In this work, the simulation of disc degeneration is based on
a finite element model of lumbar spine. A parametric study based on
mechanical properties was established, for each lumbar spine movement, by evaluating the disc degeneration in 10% steps, from healthy disc to maximum degeneration. The results show as general trend a progressive mobility increase as the disc degeneration
level raises. As main conclusion, disc degeneration
causes increased mobility at all vertebral levels, with moderate values for
incipient degeneration and much higher values for advanced degeneration,
affecting more severely to the levels closest to degenerated disk. The great
mobility increase detected at L5 could explain the instability detected as a
clinical symptom.